[GRASSLIST:2311] Re: Question about import of non georeferenced
mlennert at club.worldonline.be
Wed Aug 8 04:32:00 EDT 2001
At 19:41 7/08/01, Rich Shepard wrote:
>On Tue, 7 Aug 2001, Moritz Lennert wrote:
> > You cannot change a region once you defined it. If you want to reproject
> > data into a different projection you will have to create a new location
> > with the desired projection and project from your old location to your new
> > location (r.proj).
> Perhaps I'm particularly dense this morning, but isn't the problem more
>fundamental than this? A scanned image has no region, does it? It's just a
>bunch of bits until it is -- somehow -- georeferenced.
If I'm not mistaking, a scanned image can be imported into an x,y-location
which has an x,y-"region". It is just not projected geographically, nor
I'm not a specialist in image treatment, but the way I've always understood
it, if you do not have any more information than the basic x,y resolution
of the file, you import it into an x,y location, then leave Grass, restart
Grass with a location in the projection you want, then use i.rectify (in
combination with i.target, i.points, etc) to import/georeference the raster
image into your projected location.
Please correct me if I'm wrong.
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